On pipe joints, valves, housing closures and like structures subjected to heat and high pressure fluid conditions, it may be important that the fluid be kept from leaking from the joint and in the event of leakage, that means be provided for quick, easy and effective repair of the leaking joint. For example, repair of leaking joints in the steam pipes of a power plant presently may require time consuming disassembly to replace seal material to correct leakage at the joint.
One prior valve arrangement as disclosed in U.S. Pat. No. 3,195,552, utilizes a meltable material as a horizontal valve seat so that the seat may be reformed in situ by heating and without need for disassemblying the valve.